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CSC 7600 Lecture 1 : Introduction Spring 2011 21 Definitions: “supercomputer” Supercomputer: A computing system exhibiting high-end performance capabilities and resource capacities within practical constraints of technology, cost, power, and reliability. Thomas Sterling, 2007 Supercomputer: a large very fast mainframe used especially for scientific computations. Merriam-Webster Online Supercomputer : any of a class of extremely powerful computers. The term is commonly applied to the fastest high-performance systems available at any given time. Such computers are used primarily for scientific and engineering work requiring exceedingly high-speed computations. Encyclopedia Britannica Online

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CSC 7600 Lecture 1 : Introduction Spring 2011 22 Moore’s Law Moore's Law describes a long- term trend in the history of computing hardware, in which the number of transistors that can be placed inexpensively on an integrated circuit has doubled approximately every two years.

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CSC 7600 Lecture 1 : Introduction Spring 2011 24 Performance Performance: –A quantifiable measure of rate of doing (computational) work –Multiple such measures of performance Delineated at the level of the basic operation –ops – operations per second –ips – instructions per second –flops – floating operations per second Rate at which a benchmark program takes to execute –A carefully crafted and controlled code used to compare systems –Linpack Rmax (Linpack flops) –gups (billion updates per second) –others Two perspectives on performance –Peak performance Maximum theoretical performance possible for a system –Sustained performance Observed performance for a particular workload and run Varies across workloads and possibly between runs

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CSC 7600 Lecture 1 : Introduction Spring 2011 29 Practical Constraints and Limitations Cost –Deployment –Operational support Power –Energy required to run the computer –Energy for support facilities –Energy for cooling (remove heat from machine) Size –Floor space –Access way for power and signal cabling Reliability –One factor of availability Generality –How good is it across a range of problems Usability –How hard is it to program and manage

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CSC 7600 Lecture 1 : Introduction Spring 2011 36 Sources of Performance Degradation (SLOW) Starvation –Not enough work to do due to insufficient parallelism or poor load balancing among distributed resources Latency –Waiting for access to memory or other parts of the system Overhead –Extra work that has to be done to manage program concurrency and parallel resources the real work you want to perform Waiting for Contention –Delays due to fighting over what task gets to use a shared resource next. Network bandwidth is a major constraint.

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CSC 7600 Lecture 1 : Introduction Spring 2011 44 Addressing the Big Questions How to integrate technology into computing engines? How to push the performance to extremes? –What are the enabling conditions? –What are the inhibiting factors? How to manage supercomputer resources to deliver useful computing capabilities? –What are the hardware mechanisms? –What are the software policies? How do users program such systems? –What languages and in what environments? –What are the semantics and strategies? What grand challenge applications demand these capabilities? What are the computational models and algorithms that can map the innate application properties to the physical medium of the machine?

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CSC 7600 Lecture 1 : Introduction Spring 2011 45 Goals of the Course A first overview of the entire field of HPC Basic concepts that govern the capability and effectiveness of supercomputers Techniques and methods for applying HPC systems Tools and environments that facilitate effective application of supercomputers Hands-on experience with widely used systems and software Performance measurement methods, benchmarks, and metrics Practical real-world knowledge about the HPC community Access by students outside the HPC mainstream

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CSC 7600 Lecture 1 : Introduction Spring 2011 54 Course Website HPC Course Website can be accessed at: http://www.cct.lsu.edu/csc7600 Course Info: –Syllabus –Schedule Contact Information in the (People Section): email, IM, Phone etc. All course announcements will be made via email and Website. Lecture Slides will be made available on the course website (Course Material Section) Videos of Lectures will be made available on the course website (Course Material Section) after every lecture.

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CSC 7600 Lecture 1 : Introduction Spring 2011 57 Assignments There will be adequately portioned assignments during this course. –Assignments should be turned in as PRINTOUTS to the TA the following TUESDAY BEFORE CLASS. –Assignments should be turned in WORD format / PDF format. NO handwritten assignments will be accepted. –Assignments involving programming problems should have source code printed and attached, and all solution relevant materials (e.g. PBS scripts, commands used for performance measurement etc…) must be well documented and attached. –Source code and all relevant files for assignments involving programming assignments needs to be submitted according to the guidelines mentioned in each problem-set and is due the same time as the assignment (late policy for source code submissions is the same as that of assignments).

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CSC 7600 Lecture 1 : Introduction Spring 2011 Assignments LATE POLICY: –All assignments should be turned in on the due date BEFORE the CLASS. –Assignments turned in on the same day by 5 PM (Central) will incur a penalty of 30% of the assignment grade. –Assignments turned in BEYOND 5PM (Central) of the due date will receive 0 points irrespective of the work quality. IMPORTANT : –Most of the assignments will need to be run on local supercomputing resources that are shared among several users. –Jobs that you submit WILL get stuck in a queue. –“Queue ate my homework” is NOT an acceptable excuse for not turning homework in. –You are strongly encouraged to start working on assignments as and when they are assigned to avoid inevitable queue wait times. 58

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CSC 7600 Lecture 1 : Introduction Spring 2011 Graduate Student Projects Term projects are required for Graduate Students Sample Topics –Parallel Image Processing –Application performance measurement –Advanced visualization techniques –Parallel Programming LATE POLICY: –Abstracts turned in later than the assigned date will incur an overall project penalty of 5% –Walkthroughs done later than the assigned date will incur a overall project penalty of 15% –Projects turned in later than the assigned date will NOT be considered for grading and will have an automatic score of 0. 59

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CSC 7600 Lecture 1 : Introduction Spring 2011 61 Reference Material No Required Textbook Lecture notes (slides), required reading lists (URLs) provided at the end of lectures, some additional notes (on web site), and assignments would be primary sources of material for exams. Students are strongly encouraged to pursue additional reading material available on the internet (and as part of projects).

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CSC 7600 Lecture 1 : Introduction Spring 2011 64 Plagiarism The LSU Code of Student Conduct defines plagiarism in Section 5.1.16: –"Plagiarism is defined as the unacknowledged inclusion of someone else's words, structure, ideas, or data. When a student submits work as his/her own that includes the words, structure, ideas, or data of others, the source of this information must be acknowledged through complete, accurate, and specific references, and, if verbatim statements are included, through quotation marks as well. Failure to identify any source (including interviews, surveys, etc.), published in any medium (including on the internet) or unpublished, from which words, structure, ideas, or data have been taken, constitutes plagiarism;“ Plagiarism will not be tolerated and will be dealt with in accordance with and as outlined by the LSU Code of Student Conduct : http://appl003.lsu.edu/slas/dos.nsf/$Content/Code+of+Conduct? OpenDocument http://appl003.lsu.edu/slas/dos.nsf/$Content/Code+of+Conduct? OpenDocument